For the purposes of the following description, authentication typically is understood as the act of proving to a computer-based system (known as an authenticator) that a user is who she or he claims to be. User authentication is often based on providing user credentials in terms of three factors:                something you know (e.g., a password),        something you have (e.g., an ATM card), and        something you are (e.g., a fingerprint).        
One or more of these factors are typically verified to authenticate a user. For example, a computer user is required to authenticate himself, such as logging into his computer account, retrieving e-mail from servers, accessing certain files, databases, networks, web sites, etc. In banking applications, a bank account holder is required to provide his automatic teller machine (ATM) card as a first factor and enter a personal identification number (PIN) as a second factor in order to access an automated teller machine to conduct a banking transaction.
While in the past, users in general had to authenticate themselves, e.g., with the above factors, in a limited number of situations; the number of necessary authentications rises continuously. In addition to the above examples, computer users today have to present login/password combinations, and thus to authenticate, when accessing various web sites or services for business or personal purposes. In addition, it is increasingly necessary for someone to authenticate during further everyday tasks, e.g., when accessing security-restricted areas, including the person's workplace, gym, apartment building, etc.; when using transportation; or when shopping and subsequently paying for groceries.
Due to the high number of necessary authentications in everyday life, the latter became a quite tedious task, not only due to the effort required with the authentication processes, but also due to the necessity to safely keep a multitude of user credentials. At least in part due to the effort involved, some users, e.g., tend to choose the same credentials, such as login information, for multiple applications or choose very simple passwords, which then in turn lead to a decreased security of these applications.
Accordingly, an object exists to provide simplified authentication while keeping a high level of security.